Accelerating device



" M. J. KITrLER E-rAL Oct. v23, 1945.

. ACCELERATING DEVICE Filed Jah. 29, 194s INVENTOR.l

Patented Oct. 23, 1945 ACCELERATING DEVICE Milton J. Kittler and Ray L. Ensnger, Detroit, Mich., assignors to George M. Holley and Earl Holley Application January 29, 1943, Serial No. 474,023

1 Claim.

The object of this invention is to provide the necessary acceleration fuel in an airplane engine when the throttles are opened rapidly. 'I'hese carburetors are of such a size that a relative large quantity of fuel is required. Therefore, the accelerating device in general use which is a throttle operated fuel pump in the automotive industry, is inadequate. We have discovered that by utilizing the inlet pressure of the fuel, the necessary quantity of gasoline for acceleration can be obtained.

In the drawing Fig. 1 is a cross sectional elevation, and Fig. 2 shows the installation.

Fuel enters at I into chamber II in which is located the discharge valve I2 which is held on its seat I3 by compression spring I4. A piston I5 engages with lever I6 which when moved counterclockwise opens the valve I2. A spring Il pushes the lever I6 clockwise so that its does not engage with valve I2 which is then closed by spring I4. A stop limits the movement of lever I6 clockwise. The chamber i8 located to the right of the partition I9 is bounded on the right by diaphragm 20. Both chambers II and I8 are located in the housing 49. This diaphragm is moved by a slide piston 2| by means of the compression spring 22. Lever 23 pivoted at 24 engages with pin 25 which drives the piston 2l. A slot 25 in the housing 21 permits the pin 25 to move to the left when lever 23 rotates anticlockwise. A restricted opening 28 forms a constant open passage between the chambers II and I8. A rell valve 29 is held on side by a compression spring and permits the instantaneous refilling of the chamber I8 when diaphragm 2U is moved to the right at a very rapid rate. A valve 30 controlled by lever 3l is moved by the mixture control lever. This valve 30 is normally closed and is only opened during full idle cut off so that when an engine is shut down opening the throttle will not discharge fuel. In the position shown, the valve 33 is closed. Hence the device is operative.

In Figure 2, the accelerating device is shown located immediately above the variable venturi for which type of carburetor this accelerating device was specifically designed. This carburetor consists essentially of two throttles 34 and 35 which when closed engage with a bridge 36 in which is located the fuel passage 31 and fuel outlet passages 38 and 39. These two throttles 34 and 35 are geared together by means of gears 4D and 4I. Geared to the gear 42 is a gear 43 on which is mounted a lever 45 carrying a roller 46 which engages with the surface 4l of the lever 23. When the gear 43 is rotating anticlockwise to open throttles 34 and 35, the roller 46 engages with the surface 41 of the lever 23.

Lever 23 is thereby rotated anticlockwise. The pin 25 is then moved in the slot 26 to the left compressing the compression spring 22. 'Ihe liquid in the chamber I8 is thereby compressed under the inuence of spring 32. The effect of compression in the chamber I8 is to move the piston I5 to the left and to carry with it the lever I3 which thereby rotates anticlockwise. Valve I2 is thereupon opened and fuel sprayed out in the air entrance of the carburetor.

B'y suitably selecting the size of opening 28, the period of time during which accelerating device is operative can be varied and the minimum rate of opening of the throttles 34 and 35 determined below which this accelerating device will not operate. If the throttles are opened too fast, an excessive quantity of fuel is not discharged because a relief valve 48 is provided. When the throttles are closed, the diaphragm 20 moves to the right and fuel fills the expanded n chamber I8 by flowing past the valve 29.

y Operation I When the throttles 34 and 35 are opened quickly, the spring 22 is compressed, imposing a pressure on the liquid in chamber I8. The piston I5 compresses the spring I1 and opens the valve I2 by rotating the lever I6. The time during which the valve I2 remains open is determined by the restriction in the passage 28. The flow through this restriction permits the pressures to equalize. During the normal operation of the device, the spring loaded check valves 23 and 48 do notfunction. It is only when the lever 23 is moved at an abnormally rapid rate that the valves come into action to prevent an excessive pressure difference from being created between the chambers II and I8.

What we claim is:

A source of fuel under pressure, a chamber connected thereto by an unrestricted passage, a second fuel chamber, a restricted passage from first to second chamber, a moving wall located between said first and second chambers, spring means engaging with said moving wall, a second moving wall, located on the outside of said second chamber, manual means for engaging with said second moving wall to change the volume of said second chamber, a fuel outlet from the first chamber, a valve in said outlet operatively connected to said rst moving wall, said manual means being adapted to open said valve for a predetermined period of time determined bythe restriction between the two chambers and by said spring means when the volume of fuel in the second fuel chamber is suddenly changed. MILTON J. KIT'ILER.

RAY L. ENSINGER. 

